Evaporator



y 1941- J. L. CAMPBELL 2,243,307

' EVAPORATOR Original Filed Sept. 20, 1929 of ice trays or otherreceptacles.

- Fig. 1, may be formed in the evaporator. An overflow spout 25 communi-Patented May 27, 1941 I EVAPORATOR Jackson Lee Campbell, Wichita, Kans.,assignor to Sears, Roebuck and 00., Chicago, Ill., a corporation of NewYork Original application Sep N0.394,011.' Divided 6, 1939, Serial No.

tember 20, 1929, Serial and this application June Claims. ((31.62-126)This application is a division of my co-pending application Serial No.394,011, filed September 20, 1929, now matured into Patent No.2,210,898.

My invention relates to refrigeration apparatus and has to do moreparticularly with an evaporator designed especially for use in acontinuous absorption system, although, as will be readily understood bythose skilled in the art, my invention is not limited to such a systemof refrigeration.

A particular object oi my invention is to provide an evaporator whichwill efliciently eifect heat transfer from a liquefied refrigerant inthe presence of an inert gas.

Another object is to provide a device of the type referred to which willbe simple in construction, easy to fabricate, and, in 'generaLentirelysatisfactory for the purposes desired.

Referring now to the drawing forming a part of this specification andillustrating a preferred embodiment of my invention:

Fig. 1 is a vertical sectional view of an. evapo-i rator embodying myinvention, ated parts being shown fragmentarily, and

Fig. 2 is a similar view taken substantially 'along the line 2--2 ofFig. i.

Numeral i0 represents generally a refrigerator cabinet having a foodcompartment i2 in which is disposed an evaporator, indicated generallyby the numeral l5, embodying my invention.

The evaporator'comprises a substantially rectangular casing l6 of metalor other suitable material of good heat conductivity, heat exchange finsl8 extending around the to bottom and side walls thereof. The'evaporator may have an open ended compartment 20 for the reception Aconduit 2 I leading from a condenser or other suitable source of liquidrefrigerant extends through the top wall of the evaporator anddischarges into a well 23. This well,'as shown in part by a side wall ofcates with the upper portion of well 23 and discharges ontothe uppermost.of a series ofbailie plates 21 arranged in an evaporating chamber 28laterally adjacent the compartment. These baflie plates'are alternatelyinclined in opposite directions and are provided with outlet openings 30adjacent their lower ends, so that liquid which is discharged from thewell 23 onto the uppermost bafiie plate 21 flows downwardly," thenthrough the orifice 30, and then similarly from one baflie plate toanother until it reaches the municating with the bottom of theevaporating chamber 28 is a discharge conduit 32!.

A conduit 35, concentric with the conduit 32 and larger than the same,communicates with a substantially as follows:

Liquid refrigerant is introduced, as from a condenser (not shown),through conduit 2| into the well 23 while hydrogen or other inert gas isintroduced through conduit 35 into the flue 31 and thence into theevaporating chamber 28, where it mingles with the liquid refrigerantwhich is poured into the evaporating chamber through overflow spout 25.The reservoir 23 provides a substantially constant supply of refrigerantto the evaporator plates and tends to prevent certain associfloodingthereof. Theinert gas, admixed with the liquid refrigerant. flowssuccessively down the plates 21 until it reaches the bottonLof thechamber, evaporation taking place in the course of the flow until themixture of inert gasand refrigerant gases is discharged through theconduit 32, whence it passes into a suitable absorber 'where therefrigerant will be absorbed and the.

inert gas will be returned to the evaporator via conduit 35.

The-inert gas operates within the evaporator according to Daltons law ofpartial pressures, which is now well understood. According to this law,the partial pressure of any gas in a mixture hydrogen or other inertgas,fthere will immediately be a tendency for the liquid to evaporateand thus exert its own vapor pressure, keeping the total pressureconstant. Thus, the presence of the inert gas enhances the evaporationof the refrigerant. Since the bottom 01' the evaporating bottom of the,evaporating chamber 28. Comchamber is open to discharge, the maximumvapor pressure of the refrigerant will never be reached and hence acondition of equilibrium can neverbe obtained and the evaporation willcontinue at a maximum rate- Evaporation is also enhanced by thecircuitous route which must he traveled by the liquid refrigerant inpassing from the top to the bottom of the evaporatingchamber. There isthus established a continuous circulation through the evaporator ofinert gas admixed with refrigerant, the combined gasesbeing dischargedat'the bottom through the conduit 32.

Various modifications and variations coming within the spirit of myinvention may suggest themselves to those skilled in the art, and henceI do not wish to be restricted to the specific form shown or usesmentioned, except to the extent indicated in the appended claims, whichare to be interpreted as broadly as the state of i tuting the soleoutlet therefrom, said gas conducting means and said discharge meansbeing disposed in heat exchangerelation.

2. A. combination as defined in claim 1,- wherein the means forconducting an inert gas to the top of the chamber consists of a fluehaving one wall in common with said well and a wall in common with saidevaporating chamber.

3. In combination, in a refrigeration unit, a substantially rectangularcasing comprising a substantially rectangular evaporating chamber havinga plurality of vertically spaced apertured plates, alternate platesbeing oppositely tilted from horizontal position to promote the flow andevaporation of refrigerant, a substantially rectangular cooling chamberin heat exchange relation to said evaporating chamber, means for feedingrefrigerant liquid and means for feeding inert gas to the uppermost ofsaid plates, and means for discharging mixed refrigerant and inert gasfrom said refrigerant chamber. Q

4. In combination, in a refrigeration unit, a substantially rectangularcasing comprising a substantially rectangular evaporating chamber havinga plurality of vertically spaced a'pertured .plates, alternate platesbeing oppositely tilted from horizontal position to promote the flow andevaporation of refrigerant, a substantially rectangular cooling chamberin heat exchange relation to said evaporating chamber, a refrigerantwell formed. integrally with said evaporating chamber, overflow meansfor conducting liquid refrigerant from said well to the uppermost ofsaid plates, a fine for inert gas disposed between said well and therefrigerant chamber and discharging to the space above the uppermost ofsaid plates, and means for discharging mixed refrigerant and inert gasfrom the lower portion of said refrigerant chamber.

5. In combination, in a refrigeration unit, a

substantially rectangular casing comprising a.

substantially rectangular evaporating chamber having a plurality ofvertically spaced apertured plates, alternate plates being oppositelytilted from horizontal position to promote the flow and evaporationof'refrigerant, a substantially rectangular cooling chamber in heatexchange relation to said evaporating chamber, arefrigerant wellformedintegrally with said evaporating chamber, overflow means for conductingliquid refrigerant from said well to the uppermost of said plates, aflue for inert gas disposed between said well and the refrigerantchamber and discharging to the space above the uppermost of said plates,means for discharging mixed refrigerant and inert gas from the lowerportion of said refrigerant ch'amber,-said discharge means constitutingthe sole outlet from said evaporatingchamber, and means in heat exchangerelation with said discharge means for conducting inert gas to saidflue.

JACKSON LEE CALIPBELL.

